Ceramic matrix composites (CMC) are materials comprised of a continuous reinforcing phase (ceramic or carbon fibers) embedded in a ceramic phase (matrix). CMC materials exhibit physical properties and characteristics that are desirable for many military and industrial technical applications. Such physical properties and characteristics include, for example, high-temperature stability, high thermal-shock resistance, high hardness, high corrosion resistance, light weight, nonmagnetic and nonconductive properties, and versatility in providing unique engineering solutions. CMC materials can be used, for example, in industrial electric equipment, aircraft, spacecraft, automobiles, electronic devices and equipment, precision machine equipment, and high temperature structural members.
As one particular non-limiting example, CMC materials have been used in thermal protection systems (TPS). Conventional TPS are often employed in aerospace systems, such as engine exhaust ducts, nose cones, re-entry shield surfaces, etc., which are exposed to high temperatures or large temperature gradients. TPS conventionally employ a multi-component “mosaic” structure comprising a plurality of insulative CMC panels or tiles that are attached to the surface of a structure or member that is intended to be protected by the TPS. One example of such a TPS is found on the outer surfaces of the re-useable space shuttles used by NASA. During manufacture of the space shuttle, the plurality of insulative panels are conventionally disposed in such a manner as to provide a predetermined amount of space between each panel to allow for thermal expansion of the tiles without interference between adjacent panels at high temperatures. These spaces between the panels are conventionally covered to improve aerodynamics and reduce drag. For example, U.S. Pat. No. 5,560,569 to Schmidt discloses a TPS employing a gap cover or gap cover webbing to cover the thermal expansion gaps between thermal panels. It would be desirable to provide a compliant and flexible sealing structure comprising a CMC material in the spaces between the panels. However, conventional CMC materials suffer from low flexibility.
Thus, many applications requiring high temperature resistance may benefit from a CMC structure of relatively high flexibility.